Preparation and Characteristics of Ca2NaMg2V3O12:Sm3+ Single-Phased White-Emitting Phosphors

Novel single-phased phosphors Ca₂NaMg₂-V₃O₁₂:xSm³⁺ that exhibit efficient white-light photoluminescence properties have been successfully synthesized by the solid-state reaction method. The formation of a single Ca₂NaMg₂V₃O₁₂ phase has been confirmed by X-ray powder diffraction (XRD). The wavelength-tunable white light is realized by coupling of the broad emission band at 500 nm due to a V⁵⁺?O^2? charge-transfer state transition and the sharp emission peaks at 564, 616, 650 and 708 nm assigned to ⁴G_5/2→⁶H_J (J = 5/2, 7/2, 9/2, 11/2) transitions of the Sm³⁺ ion. The luminescence color can be tuned from green to white by adjusting the doping concentration of Sm³⁺. When the doping concentration of Sm³⁺is increased from x = 0 to x = 0.20, the color rendering index of the Ca₂NaMg₂V₃O₁₂:xSm³⁺ phosphors increased from 55 to 83. The present white phosphors show a great potential for white LEDs.